Automatic diamond cutting and polishing machine.



E. LEPERRE.

AUTOMATIC DIAMOND CUTTING AND POLISHING MACHINE.

APPLICATION FILED OCT. 20. I913- l fifi m 7D I Patented Apr. 9, 1918.

4 SHEETS-SHEET 1.

I I l 11% E. LERERRE. AUTOMATIC DIAMOND CUTTING AND POLISHING MACHINE.

APPLICATION FILED OCT.'20| I913.

1362 2170 Patented Apr. 9, 19m

4 SHEETS-SHEET 2- E. LEPER .v

AUTOMATIC DIAMOND CUTTIN LISHING MACHINE.

APPLICATION FILED .1913. 1,,%2,21 7o Patented Apr. 9,1918..

4 SHEETS-SHEET 3- E.LEPERRE.

AUTOMATIC DIAMOND-CUTTING AND POLISHING MACHINE.

APPLICATION FILED on. 20. 1913.

1 262 21 70 Patented. Apr. 9, 1918.

4 SHEETS-SHEET 4.

ran erars Parana @FFTE EMILE LEIEEBRE, 0F BERCI-IEM ANTWEBP, BELGIUM.

AUTOMATIC DIAMOND CUTTING AND POLISHING MACHINE.

To all whom it may concern:

I Be it known that I, EMILE LEPERRE, en gineer, a subjectof the King ofthe Belgians, and resident of 46 Rue du Champ, Berchem-Antwerp, Belgium,have invented a certain new and useful Automatic Diamond Cutting andPolishing Machine, of which the following is a specification.

This invention relates to machines for cutting diamonds in which thediamond is carried by a stick or holder which can be adjusted at varyingangles to the plane of the cutting surface on the wheel or lap for thecutting of facets on the stone in varying positions and can be adjustedabout its own axis for the cutting of series of such facets.

. The invention has for its objects to provide an improved machine theoperation of which is largely automatic, thus reducing the cost oflabor, while at the same time the diamonds can be cut with the maximumof symmetry. The machine is such that it can be used for the cutting ofdiamonds which hitherto it was found impossible to cut.

According to the invention means are provided for indicatingmechanically the progress of the cutting operation, consisting of amicrometer mounted under the action of a spring and held in position byan adjustable abutment maintained in determined relation to the diamond,in such manner that, when the thickness of the diamond diminishes duringthe cutting operation, the abutment is moved accordingly and permits themicrometer to move under th action of its spring. r

Accordingto the invention, also, the micrometer may be provided as abody with a graduated disk carrying a cursor or slider which can beadjusted according to the thickness-which is required to be removed fromthe 'diamond.

According to the invention, also, the

diamond is withdrawn automatically from the cutting wheel orlap when.a-facet has acquired the ,size determined by. the mi crometenf The dopis mounted upon a carrier which is reciprocated togive the dop a similarmovement in a. direction parallel to the plane of the cutting surface atthe point Specification of Letters Patent.

Patented Apr. 9, 1918.

Application fied October 20, 1913. Serial No. 796,323.

of contact of the diamond with the said surface. On the completion ofthe cutting of a facet the adjustable cursor or slider of the micrometercloses the circuit of an velectromagnet or solenoid which thereuponmoves an obstructing member into the path of a projecting member on thedop carrier. The said members are so formed that in the reciprocation ofthe dop carrier or frame, the projecting member is forced below theobstructing member and thus carries the dop carrier to an inoperativeposition where it reached the size of the first facet.

According to the invention the dop is mounted upon the carrier throughthe medium of a member having a truncatedcone portion adapted to fitinto a corresponding seating in the carrier, the diamond beingmaintained always on the axis of the cone. Thus it is possiblecompletely to rotate the diamond while it is beingcut withoutwithdrawing it from the cutting surface. In order however, that this maybe possible for all positions of the dop, whatever its angle withrespect to the cutting surface, the dop is formed with a sector adaptedto fit in a corresponding groove or slot formed 1n the memberv havingthe I truncated cone in such manner that the axis of the dop can'beplaced at different angles while the diamond is maintained at the axisof the cone.

According to'the inventiomalso, the'combination of adop mounted in themanner described with. the micrometer mechanism permits the bestdirection for cutting a diamond to be readily and. accurately jdetercenter of curvature ofthe sector and onfthe mined as it is onlynecessary, after having adjusted the micrometer, to rotate the diamondabout the cone axis of the dop mountmg until it is in a position inwhich the micrometer is observed to move most rapidly.

There are many diamonds, known as naths, which are composed of severalcrystals-bound together and these cannot be cut by the most experiencedcraftsmen with the means usually employed. With the mechanism accordingto the invention it is not necessary to know the structure of the stone,the direction in which it should be out being determined automatically,while the cutting can be effected with as much ease in one direction oranother without altering the adj ustment of the mechanism.

According to the invention, also, the diamond can be completely finishedwith only two settings. This is due to the particular mechanism providedfor holding the diamond in position. The dop is provided with eightholes or seatings in which can be inserted claws in the form of feetadapted to engage the sides of the diamond, three claws su cing tomaintain the diamond rigidly in position so that it is always possibleto remove a claw from a particular part of the diamond which it may bedesired to out. In this way the upper and lower sides of the diamond canbe out without removing it from the dop. Again, a single claw may beemployed adapted to press upon the table of the diamond, such claw beingmounted adjacent the dop in such manner as to move with the dop when itsaxis is moved while permitting independent rotation of the dop about itsaxis for the cutting of the facets at the side of the table of thediamond.

In order to make the explanation given hereafter as clear as possiblethere are annexed drawings which show one form of the machine providedaccording to the invention', such machine being provided with acylindrical cutting wheel or lap, which is preferable to the usual diskor plate lap.

Figure 1 isa general view of the machine,

Fig. 2 is a side view of the block,

Fig. 3 is a front view of the block,

F igs. 1 and 1 show details of the regulating d'evice,

' ig. 5 shows details of the pressure regu- 'lating device with thesafety stop,

Fig. 6 is a sectional view of the block sup- P Fig. 7 is a section ofthe dop,

Fig. 8 is a semi-development of the dop dividing-plate,

Fig. 9" is a plan view of the top of the dop,

Fig. 10 shows details of the claws,

Fig. 11 is a plan View of the Vernier serving to regulate the heightof'the sleeve 43.

' The wheel 1 (Fig. 1) revolves at a speed of about 2,000 revolutionsper minute. The inner peripheral face thereof is coated with diamondpowder. During cutting the diamond held by the block 2 is constantlypressed against the inner peripheral face of the cylindrical wheel 1.

The block 2, the various members of which are hereinafter described,slides in a groove provided in the block support 6. The slots in theblock support 6 are shown in Fig. 6. Reciprocating motion is imparted tothe block 2 by means of the helicoidal slot 11 in the bush 12 forming acam.

The cam 12 revlove's at the rate of about 25 revolutions per minute onthe shaft 13.

The cam 12 is secured in position upon the shaft-13 by means of collars1 1 and 1 1.

The shafts 13 and 13 are mounted in bearings 15 and 15.

The bearings of the wheel 1 are arranged at the inner ends of the shafts13 and 13.

The roller 16 can be disengaged from the slot 11 so as to be able toslide the cam and collars ofi the shaft and remove the dop 7 from themachine (Fig. 2).

The diamond 17 (Figs. 7 and 9) placed in the cup 18 is secured inposition by means of claws 19 for cutting the table and the lower faceof the diamond, and by means of ;he claw 20 (Fig. 10) for cutting theother acets.

It is' possible to completely out the diamond by securing the same .inposition by means of the claws 19 only.

The claws 19 serve for the purpose of keeping the stone in positionduring cutting so that in order to be able to cut, the diamondcompletely it is only necessary to re-adjust the stone once that is tosay for the purpose of cutting the pavilion or lower face of thediamond. To effect this the dop is provided wit-h eight holes drilled atequal distances within which the claws 19 can be securely mounted. Theseclaws secure the stone to be cut in position by pressing against theedges thereof but, if desired, another claw 20 may be substituted whichsecures the stone by pressin against the table.

The op 7 is capable of revolving on its axis within the limits of thesector 2 The inner member 52 (Fig. 7) ofthe dop is capable of beingdisplaced eccentrically to the axis of the outer member 53 of the dop.The sector 21 (Fig. 3) is capableof sliding in a slot provided in a bentpart 22, so that. it is possible to dispose the axis of-the dop atvarious angles while keeping the diamond in the center of the radius ofthe sector 21.

A graduated plate 23 shows the degree of inclination of the dop.

Underneath the dop there is arranged a each acet "of the diamond byplacing the line corresponding to each facet exactly opgraduated ring 8which is capable of being posite the pointer 24. A screw 25 serves toclamp the sector 21 to the member 22.

The whole of the dop and of the cylindrical part 22 can be easilyremoved from the dop frame 26, and be replaced in position byintroducing the cone of the sector support 22 into a conical openingprovided on the frame 26.

The frame 26 is movable on a fixed plate 27.

Two ball bearings 28 and 28 guide the motion of the frame26 on the fixedplate 27.

A spiral spring 29 constantly tends to press the frame 26 away from theplate 27 and consequently to press the diamond against the wheel.

The spring 29 (Fig. 5) is arranged in a threaded bush. A milled nut 31enables the pressure ofv the spring 29 to be regulated. A rack 32 (Fig.2) serves to support the frame 26 when the diamond is moved away fromthe wheel.

A facet regulator or micrometer (Figs.

4 and 4*) is arranged within the members 26 and 27. The said micrometerconsists of a graduated disk 34 formed integral with a hollow screw 33which is screwed into the plate 27.

A torsion spring 35 arranged within the screwed sleeve 33 tends tounscrew the latter (33). The screw 36 secures one of the ends of spring35 to the plate 27 while a screw 37 secures the outer end of the spring35 to the disk 34. l

The milled nut 39 serves to adjust the recoil spindle 38.

An index stop 40 (Fig. 4 is adjustably secured to the disk 34 and aprojection thereon can contact with a stop at the end of an insulatingplate 41, mounted on the plate 27 and electrically insulated from thelatter.

Within the members 26 and 27 there is also arranged an adjustable safetycatch 65 (Fig. 5). I

A spindle 42 has its lower end secured 'to the plate 27, while the otherend is threaded. A bush or sleeve spindle 42. I

1The roller 44 serves to adjust the height of the sleeve 43. The head ofthe latter sleeve can contact with the shoulder 45 of the frame 26. Onthe side of the frame 26 there is arranged a roller 46 (Fig. 3).

Qn the member6 (Fig. 3) opposite the roller 46 there is mounted anelectro-magnet 43 is screwed on the 47 which is capable of beingdisplaced and adjustedin relation to the length d the height of'theblock 2; j v j The'core 48' of the electrmmagnet" pro- 4 jects partlyfrom the solenoid 49 by means 'of the spring 50. 1 51 of the core 48 ismade of v The end copper.

catch 55 engaging a rack 32 so as to sup port the frame 26 when thediamond has i been moved away from the cutting surface of the wheel.

Automatic cutting takes place as follows:

The diamond is placed table upward in the cup 18 and secured in positionby means of the claws 19; after having adjusted the sector 21 at thezero position, that is to say, so that the axis of the dop shall be inalinement with that of the cone 54 of the bent sector support 22, thedop is placed in position by introducing the cone 54into the conicalopening in the frame of the block 2.

The dop is then lowered by pressing on the member 26. The catch 55 thenengages one of the notches of the rack 32 and thus supports the member26.

After having introduced the diamond into the wheel 1, the roller 16 isplaced in the slot 11 of the cam 12 in order to impart to the block 2 areciprocating motion; the catch 55 is then disengaged and owing to thepressure of the spring 56 .the diamond is pressed against the wheel andthe recoil spindle 38 is adjusted so that after having screwed down thedisk 34 by about one revolution corresponding to. a distance of 1 mm.equal to the distance between each of the threads 33, the disk can onlybe raised by the spring 35 to the extent of one half-revolution.

The torsion of the spring 35 is not strong enough to overcome thepressure of the spring 56 which raises the recoil spindle 58 until thelatter is stopped by the pin 57 on the spindle or sleeve 58; the pin 57engaging the closed end of a slot provided in the recoil spindle 38.

While the diamond is being cut, the mem ber 26 gradually rises from themember 27, while the micrometer disk 34 owing to the action of thespring 35 slowly revolves, the index stop 40 approaches the stop 41(Fig. 4 1

The circumference of the micrometer disk '34 is divided into 200 equalparts; therefore when the index slider has approached the stop 41 to theextent of one division, a thickness of th of 2. mm. will have been takenoff the diamond. j j

When starting to cut a facet, the distance between the index slider 40and the stop 41 is adjusted according to the amount to be taken'off thediamond.

In order to find the best direction for cutting, the sector support 22(Fig.3) is slowly rotated until the index slider 40 approachesclose tothe stop 41.

The electro-magnet 47 is adjustedso that the end 51 of the core is about2 mm. lower than the top peripheral edge .ofthe roller 46.

'VVhen the index slider 40 contacts with the diamond is of the requiredsize, an electric circuit passing through the solenoid 49 is closed. Thecopper end 51 of the mildiron core 48 projects either in the path of orclear of the roller 46, according to whether the electric circuit iscompleted or not.

Through the reciprocating motion imparted to the block 2, the lattercauses the roller. 46 to pass underneath the end 51 of the core, thelatter being lower thanthe and remains out of contact therewith owing tothe catch 55 engaging a notch of the rack 32.

The table of the diamond being completed, the dop is placed. at asuitable angle, according to the thickness of the stone. One of theclaws 19 securing the diamond is then removed and the dop 7 is turned onits axis so that the side of the diamond from "which the claw wasremoved can be placed against the wheel. 1

For the purposeof cutting a fairly large diamond the claw 20 may be usedby securing the point thereof on to the table of the stone, the claws 19not being then required. Tlfe claw 20 is arranged in a support 59 fixedon to the sector 21, so that the dop is the table. d

capable of rotating on its axis while allowing the claw to press on thediamond.

Since-the stone is arranged in alinement with the axis of the cone 54 ofthe member 22, the cutting of all the facets of stone is proceeded within the .same manner as for The first side facet of the diamond being cutthe desired size, the graduated ring 8 arranged on the dop 7 is turnedso that one of its dividing lines 60 (Fig. 8) (which divide the ring ineight equal parts). is exactly opposite the index 24; the ring is thensecured in position by means of the clamping screw 64.

Before startin the safety stop Fig. 5) is adjusted so that contactswithQthe shoulder at the top of the.

the frame 26 cannot'eontinue to ascendwhen the index slider 40;;contacts against the stop 41. The safety stop is -ad usted by pressing down thesleeve 43 s'o-that the shoulder 45 sleeve 43 when the index slider 40touches the contact 41.- Should the contact 41 be-- come clogged andthus preventing'the closing of thesolenoid circuit the stone cannot beremoved from the cutting surface, the

safety stop prevents the stone from being out further when the faetis'of the required size.

- r In order to cutthefsecondside facet, the

dop is turned 4th and the process is the same as forthe firstone, and asthe first. eight to cut the second facet,

facets (called corners,) have to be exactl allke, 1t is no longernecessary to make ad justment until the table of the diamond hasvision-lines 60 and therefore divide the ring into 16 equal parts, areplaced opposite the pointer 24, and the process is the same, as forcorners.

The sixteen dividing lines 62 in the center of the divisions formed byone dividing line 60 and one dividing line 61 and which therefore dividethe ring in thirty-two equal parts serve to guide the cutting of facetscalled"fences.

Should the diamond not be set accurately in the center of dop; in orderto prevent its having to be loosened the member 52 is capable of beingmoved eccentrically in order What I claim and desire to secure byLetters Patent of the United States is 1. In a diamond cutting machine,a stone support, a cutting surface, a carrier on which said support ismounted, spring means cooperating between said carrier and said supportto press said support toward said cutting surface and indicating meansforming a part of said spring means whereby the rate and extent ofmovement of toward said cutting surface may be determined. I

2. In a diamond cutting'machine, a carrier, a worm carried thereon, aspring cooperating between said carrier and said worm to advance saidworm, a cutting surface, a stonev support mounted on said carrier wormto advance said worm,'a cutting surface, a stone support mounted on saidcarrier and adapted to be moved toward said cutting surface by theadvance of said-worm, a scale wheel or micrometer attached to' to re-setthe diamond in the axis of the dop.

said support said worm whereby the rate and extent of advance of saidworm and support are indi-v cated and-means carried by said scale wheelfor closing an electric circuit when it reaches a predeterminedposition.

4. In a diamond cutting machine, a cut-- ting surface, a carrier, astone support o mounted on said carrier and capable of re ciprocalm'ovement thereon toward and from' said cutting surface, a spring onsaid carr er serving to press said support toward said cutting surfaceand a micrometer device interposed between said spring and said suptohold the stone to be out against s ting surface, a carrying element andmeans forming a part of one of said .elements and cooperating with theother of said elements for rotatably mounting said supporting element onan axis perpendicular to said cutting surface passing through the centerof the stone to be cut when in position in said supporting element.

6. In a diamond cutting machine a cutting surface, a stone support,"acarrier for said support and means cooperating between said support andcarrier whereby said support can be completely rotated while thecutting'operation is going on without movement of said support to orfrom said cutting surface.

7. In a diamond cutting machine a cutting surface, a stone support, acarrier provided with a conical recess, the axis of which isperpendicular to said cutting surface and a truncated conical extendingportion forming a part of said support the axis of which is coincidentwith the axis of the stone when in' position on said support, saidtruncated portion and said recess forming means whereby said support maybe completely rotated without movement to or from said cut-v tingsurface.

8. A machine for cutting diamonds in which the progress of the cuttingoperation is indicated mechanically, comprlsing a micrometer, a movableabutment for the said micrometer and means by which the said micrometeris moved as the cutting operation proceeds, substantially as described.

9. A machine for cutting diamonds, in

\ which the .progress of the cutting operation is indicatedmechanically, comprising a micrometer, consisting of a body carrying agraduated dlsk and a cursor or slider, means forthe adjustment of thecursor or slider ac-' cording to the thipkness which is required to beremoved from the diamond,a movable abutment for the said micrometer andmeans by which the saidmicrometer is moved as the cutting operationproceeds, substantially as described.

10. A machine for cutting diamonds in which the progress of the cuttingoperation is indicated mechanically comprising a micrometer, a-movableabutmeiit for the said micrometer, means by which the said micrometer ismoved as the cutting operation proceeds and automatic means for therecut- 1 ciprocation of the dop carrier by which a movement isimparted'to it parallel with the plane of the cutting surface at thepoint of contact of the diamond with the latter, substantially asdescribed.

v 11. A machine for cutting diamonds in which the progress of thecutting operation is indicated mechanically, comprising a ceeds andmeans by which the diamond is withdrawn from the cutting wheel when afacet has acquired the size determined by the micrometer, substantiallyas described.

12. In a stone carrier for diamond cutting machines a stone supportprovided with recesses, and a stone holding claw provided with acylindrical shank adapted to be inserted in one of said recesses and tobe held therein by lateral presure produced by the pressure of the endof said claw against the stone to-be cut.

13. In a stone carrier for diamond cutting machines, a stone sup ortprovided with a cup in which the stone to be cut is adapted -to beplaced and recesses adjacent thereto being adapted to be inserted in oneof said recesses and to be held therein by lateral ressure produced bythe pressure of said oldin portion against the stone to be cut. 14:. n astone carrier for diamond cutting machines, a stone support providedwith 'a cup in which the stone to be cut is adapted to be placed, arotatable mounting for said support the axis of rotation of saidmounting being coincident with the axial dimension of said cup, and astoneholding claw comprising a laterally extending holding portionresting when in position in a line with the axis of said rotatablemounting, and a cylindrical shank portion insertible in a recessprovided in said support and held therein by lateral pressure producedby the pressure of said holding portion against the table of the stoneto be cut.

In testimony whereof I have hereunto signed my name to thisspecification in the presence of two subscribing witnesses.

EMILE LEPERRE.

